I Am Number Four (Lorien Legacies #1) by Pittacus Lore
The Power of Six (Lorien Legacies #2) by Pittacus Lore
The Rise of Nine (Lorien Legacies #3) by Pittacus Lore
The Fall of Five (Lorien Legacies #4) by Pittacus Lore
I Am Number Four: The Lost Files: The Fallen Legacies by Pittacus Lore
I Am Number Four: The Lost Files: The Search for Sam by Pittacus Lore
I Am Number Four: The Lost Files: The Last Days of Lorien by Pittacus Lore